Inside The Impossible Job Of Writing “Avengers: Infinity War”

The cast and crew of Avengers: Infinity War at the Los Angeles global premiere on April 23, 2018.

Jesse Grant / Getty Images

The notion that Avengers: Infinity War is the most ambitious crossover event in history has spawned an entire ecosystem of skeptical memes, but also, let's face it, it's completely true. With roughly 40 significant roles, pulling from storylines spanning 18 separate movies over the last 10 years, Infinity War is unlike any feature film ever attempted by Hollywood.

At the front lines of that effort: screenwriters Christopher Markus and Stephen McFeely. The duo — who cut their teeth on franchise filmmaking with three of the Chronicles of Narnia movies — started working at Marvel Studios in 2008. They've written all three Captain America movies, as well as 2013's Thor: The Dark World, and they helped create the spinoff series Agent Carter for ABC. Which is to say, they've been as steeped in the world of the Marvel Cinematic Universe as just about anyone short of studio chief Kevin Feige.

For what has been billed as the concluding chapter of this iteration of the MCU, Markus and McFeely were tasked with writing two films: Infinity War, opening in theaters now, and an untitled sequel due to open a year from now, both chronicling the collision between the disparate superheroes within the MCU and the designs of cosmic supervillain Thanos (Josh Brolin) to wipe out half of all life in the universe by collecting the six all-powerful Infinity Stones.

To date, the effort has consumed nearly two years of Markus and McFeely’s lives: four months developing the key story beats at the end of 2015, five months writing each screenplay, and then another year rewriting the scripts as the films entered parallel production throughout 2017.

“It was unwieldy,” McFeely told BuzzFeed News, with perfect understatement. “We started shooting before [2018 Marvel films] Black Panther and Ant-Man and the Wasp, and they both finished shooting before we were done.”

Thanos (Josh Brolin) in Avengers: Infinity War.

Marvel Studios

The center of the film, by necessity, was Thanos. “He set the story,” said Markus. “He's the driver. Once we figured out what he was doing and what he wanted to do, everyone else, we just figured out how they slotted into either trying to stop [him] or not.” But while sorting out how to thread that ginormous purple-faced needle, Markus and McFeely also had great fun playing with all the characters in the MCU — quite literally.

While working on the script, the pair holed up inside a vast conference room in Marvel Studios headquarters, one entire wall of which was filled with baseball cards featuring every character within the MCU. Then the screenwriters shuffled them around to figure out who should be matched up with whom. “We knew we didn't want 25 people in a room, 25 people in a room, 25 people in a room,” said McFeely. “We thought smaller stories that weave together. They're all pretty simple, because it's about somebody's coming for your stuff. But by weaving them together, it will feel complex.”

Handling the classic Avengers — Tony Stark (Robert Downey Jr.), Captain America (Chris Evans), Thor (Chris Hemsworth), the Hulk (Mark Ruffalo), and Black Widow (Scarlett Johansson) — was second nature for the duo. The bigger challenge was incorporating the characters who’d remained largely on the fringes of the MCU before now. Here’s how they did it.

Opening three months after Black Panther started as a potential curse, and then became a massive blessing.

Marvel Studios

Of the many hurdles facing Markus and McFeely, one of the most daunting was the knowledge that their film would be coming out just months after Black Panther — and yet given the enormous size of both films, they had to start their writing process before Ryan Coogler and Joe Robert Cole began writing Black Panther.

“We're writing a story that has a substantial action sequence that takes place in Wakanda, but we know that three months earlier, [Black Panther is] probably going to have an action sequence that's going to take place in Wakanda,” said McFeely. “We thought, Are we repeating ourselves?Are they any other options? There were none better than what we had for the story. So we went with it.”

A battle scene in Wakanda in Avengers: Infinity War.

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Markus and McFeely said while they did speak with Coogler and Cole, their main conduit for intel on Black Panther was executive producer Nate Moore, who'd worked with the screenwriters on the previous two Captain America films. “We would ask permission: Is this ridiculous or cool?” said McFeely.

Of course, the world now knows that Black Panther was nothing less than a historic phenomenon. “We felt a little smart and lucky,” said McFeely with a laugh. “It feels pretty cool that people are excited about [seeing Wakanda again], as opposed to, Oh god, we've got to go to this place again.”

That was especially true of their decision to give the Black Panther character of Shuri (Letitia Wright) a crucial role in the film's third act. “We didn't know that Shuri was going to become a beloved national treasure,” said McFeely. “But we knew that she played an integral part, and we could use her.”

One big moment in Black Panther connected deeply with the core theme of Infinity War.

Chadwick Boseman in Black Panther.

Marvel Studios

At the end of Black Panther (spoiler alert for a movie literally everyone has seen), the titular hero T’Challa decides to reveal to the world his country’s true nature as the most technologically advanced society in the world, after defeating Erik Killmonger (Michael B. Jordan), who wanted to do just that (but with bombs). “I've never seen the hero change his mind even after defeating the villain,” said McFeely, in awe. “It's fascinating.”

T’Challa’s decision also has massive, and ominous, repercussions in Infinity War — it’s one of the reasons Markus and McFeely chose to set the film’s final act in Wakanda.

“One of the themes of the movie is the cost of your own heroism,” said McFeely. “What are you willing to do to get what you want, and given how you behave, what are the consequences? Bad things are now going to happen because you've chosen to be a hero to the world, and not just a country.”

The Black Panther cast contributed one of the film’s most chill-inducing moments.

Arguably the most effective piece of marketing in the massive promotional blitz for Infinity War has been the TV ad (which you can view above) in which T’Challa leads the Wakandan forces in a war chant against Thanos’s mounting horde. And it was all the actors’ idea.

“Yeah, we did not write any chants,” said McFeely. “[The actors] showed up on set and said, ‘We do this thing,’ and he goes, ‘Yibambe!’ And everybody went, ‘Holy crap!’ My hair stood on end. ‘Do that!’ It was really like Wakanda came to the movie.”

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Given their extensive experience within the MCU — including introducing T’Challa in 2016’s Captain America: Civil War — there were only two major franchises whose title characters Markus and McFeely had not yet written for: the Guardians of the Galaxy — Peter Quill (Chris Pratt), Gamora (Zoe Saldana), Drax (Dave Bautista), Rocket (Bradley Cooper), Groot (Vin Diesel), and Mantis (Pom Klementieff) — and Doctor Strange (Benedict Cumberbatch).

For the Guardians’ particular style of snipe-y, snappy banter, Markus and McFeely consulted with two-time Guardians of the Galaxy writer-director James Gunn, and they also relied on the actors’ considerable improvisational skills. “Those actors know their characters really well,” said McFeely.

“In some ways, they were the ones we were most excited about bringing into it. It spices things up,” added Markus. “That tone is closer to real life than Iron Man talking to Captain America. That doesn't happen that often, but people are sniping at each other in my house all the time! So that was reasonably easy to sink into.”

Writing for the Guardians wasn’t just a joke parade, though. The connection between Gamora and her sister Nebula (Karen Gillan), and their adoptive father Thanos, also lent their scenes crucial dramatic weight. “Even though [the Guardians] may be the lightest and in some ways jokiest pie slice of the MCU, they're also the closest to this nightmare that's about to happen,” said Markus.

As for Doctor Strange, Markus and McFeely decided to pair him up with Tony Stark, despite how counterintuitive it might have seemed at first — and their inspiration was a classic NBC sitcom. “Two egotistical guys with goatees — is that overkill?” said Markus. “It made us think about, well, on Frasier, they had an uptight guy, and the instinct would be to make his brother, like, a truck driver. Look, it's a crazy odd couple! But they made [his brother] even more uptight, and it worked fine. So that was our inspiration.”

There wasn’t much time for character development.

Those familiar with Peter Quill’s story from the Guardians films know that the character was born on Earth, only to be whisked away from his home planet as a child, never (yet) to return. In Infinity War, Peter will meet the first humans from Earth he’s seen since that day (at least, that we know of), but don’t count on him to savor the opportunity to wax nostalgic about home.

“This is driven by a very propulsive, time-sensitive plot,” said Markus. “So we didn't have that much time for people to sit back and go, like, ‘Are there still Dairy Queens?’”

“We would love to tell the four-hour story of every plot strand coming together, and echoes from six movies ago,” added McFeely.

“As much material as there was on the side that you could have done, this giant purple guy is coming,” continued Markus. “So there was never that much available real estate to fill up with this stuff.”

Balancing characters between both Avengers movies was key.

Indeed, given the vast amount of story to cover, and characters to include, in Infinity War, Markus and McFeely are acutely aware that many fans will end up feeling frustrated by how little their favorite MCU characters made it into the film. But while they were both loath to discuss any spoilers for Infinity War, they did quite tellingly emphasize that the movie is one half of a larger story.

“[Characters] don't have the same amount [of screentime] in each movie,” said Markus. “They only get as much as the story demands for them. You might feel, I could've used 15% more Captain America there, but, like, you'd be riffing as opposed to telling a story. So I think over the span of two movies, everyone gets exactly the amount of screentime they need and deserve.”

Added McFeely, “You may walk away from movie one and go, Well, I could've used more of the character. Odds are, you'll get a lot of that character in the next movie.”

Keeping secrets is surprisingly easy when you’re the screenwriters.

Despite literally being the first people to know of many of the most critical plot and character developments in Infinity War and its sequel, Markus and McFeely said they have weathered almost no difficulty keeping those secrets to themselves.

“No one asks us crap,” McFeely said with a laugh. “No one knows who we are! We're completely invisible.”

“Everyone I see at work knows the answer, so they're not asking me,” added Markus with a weary smile. “And everyone I see at home does not give a damn. So it's like, ‘Hey, I know something about Thanos!’ ‘Uh-huh. That's great.’”